The objective of the work are in-depth experimental studies of Cu(II)
and Zn(II) ion removal on chitosan gel beads from both one- and
two-component water solutions at the temperature of 303 K. The optimal
process conditions such as: pH value, dose of sorbent and contact time
were determined. Based on the optimal process conditions, equilibrium
and kinetic studies were carried out. The maximum sorption capacities
equaled: 191.25 mg/g and 142.88 mg/g for Cu(II) and Zn(II) ions
respectively, when the sorbent dose was 10 g/L and the pH of a solution
was 5.0 for both heavy metal ions. One-component sorption equilibrium
data were successfully presented for six of the most useful
three-parameter equilibrium models: Langmuir-Freundlich,
Redlich-Peterson, Sips, Koble-Corrigan, Hill and Toth. Extended forms of
Langmuir-Freundlich, Koble-Corrigan and Sips models were also well
fitted to the two-component equilibrium data obtained for different
ratios of concentrations of Cu(II) and Zn(II) ions (1:1, 1:2, 2:1).
Experimental sorption data were described by two kinetic models of the
pseudo-first and pseudo-second order. Furthermore, an attempt to explain
the mechanisms of the divalent metal ion sorption process on chitosan
gel beads was undertaken.